Power-driven chain saw with automatic and manual lubricating pump

ABSTRACT

A power-driven chain saw having a lubricating pump for the saw chain and/or guide bar. A pump housing has a pump chamber and lubricating fluid inlet and outlet passages communicating therewith and a plunger reciprocable therein. A wobble ring having planetary elements positioned therewithin is connected operably with the plunger, said wobble ring being movable so as to cause reciprocation of said plunger. A sun element is operably connected to the drive for the saw chain and the pair of planetary elements are driven by the sun element around same and within the wobble ring. A difference in the diameter between the planetary elements results in vertical movement of the wobble ring to cause reciprocation of the plunger.

United States Patent [1 Batson 1 Oct. 29, 1974 1 POWER-DRIVEN CHAIN SAWWITH AUTOMATIC AND MANUAL LUBRlCATlNG PUMP [75] Inventor: William A.Batson, Pickens, SC.

[73] Assignee: The Singer Company, New York,

221 Filed: Feb. 19,1974

[2]] Appl. No.: 443,584

Primary Examiner-Al Lawrence Smith Assistant Examinerl. C. PetersAttorney, Agent, or FirmR0bert E. Smith; Edward L. Bell; Joel Halpern[57] ABSTRACT A power-driven chain saw having a lubricating pump for thesaw chain and/or guide bar. A pump housing has a pump chamber andlubricating fluid inlet and outlet passages communicating therewith anda plunger reciprocable therein. A wobble ring having planetary elementspositioned therewithin is connected operably with the plunger, saidwobble ring being movable so as to cause reciprocation of said plunger.A sun element is operably connected to the drive for the saw chain andthe pair of planetary elements are driven by the sun element around sameand within the wobble ring. A difference in the diameter between theplanetary elements results in vertical movement of the wobble ring tocause reciprocation of the plunger.

14 Claims, 9 Drawing Figures 20 70 se\ i 3 BACKGROUND OF THE INVENTIONThis invention relates to power-driven chain saws and more particularlyto such a saw which incorporates a gear-driven automatic lubricatingpump and a hand pump.

A typical prior art lubricating pump involves the pro vision of a pumpchamber or cylinder within the transmission housing of the chain saw andin which a plunger is reciprocated to draw lubricating oil from areservior through oil inlet passages into the cylinder from which it isdischarged to the guide rail or guide bar for the saw chain. Aneccentric member carried by the sprocket shaft is provided with a collarwhich connects with the plunger and effectuates reciprocation thereofconcomitant with rotation of the sprocket shaft.

The disadvantages of such eccentric plunger actuating mechanisms areprincipally twofold: l) the eccentric or cam mechanism tends to developa wiping action during plunger reciprocation, and (2) the plunger isforced to reciprocate with each revolution of the drive shaft, thusbeing generally limited to high cyclical operational rates. The firstdisadvantage leads to undue and uneven wear of both the cylinder andplunger with the attendant generation of heat and ultimate loss ofpumping pressure. The second of such disadvantages serves to acceleratethe wear and tear on all moving parts of the pump assembly, includingany check valves which may be utilized.

Other known pump constructions require "that a substantial area withinthe housing be allocated for the pump. Such space is at a premium,particularly in a direction axially of the shaft utilized to drive thepump mechanism.

SUMMARY or THE INVENTION One object of the present invention is theprovision of a power-driven chain saw having an automatic lubricatingpump incorporated therein which delivers metered amounts of lubricant.

Another object of the invention is the provision of a power-driven chainsaw having an automatic lubricating pump incorporated therein which iscapable of operation at a reduced cyclical rate.

Still another object ofthe invention is the provision of a power-drivenchain saw having an automatic lubricating pump incorporated thereinwhich generates a reduced amount of heat and has an increased serviceThese and other objects and advantagesoftheinvention will becomereadilyapparent from the description of the invention whichfollows'hereinafter.

According to this invention there is provided in a power-driven chainsaw having a saw chain and a saw thereon, a sprocket shaft rotatablysupporting said 2 chain, a guide bar for guiding said saw chain along apredetermined path, and a lubricating pump which includes a reeiprocableplunger for supplying lubricant for said saw chain, the improvementwhich comprises:

a. a wobble ring mounted so as to cyclically reciprocate said plunger ina predetermined time-phase relationship with the rotation of said sawchain;

b. a sun element mounted within said wobble ring operably connected tothe driving means for said chain saw; and

c. at least one planetary member interposed between said sun element andsaid wobble ring, the relationship between said planetary member andsaid wobble ring being such that said planetary member rotates withinsaid wobble ring to periodically reach positions therewithin wherebysaid wobble ring is caused to rise and fall and thus cause reciprocationof said plunger.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may bemore fully comprehended it will now be described, by way of example,with reference to the accompanying drawings in which:

FIG. I is a perspective view of a power-driven chain saw embodying theinvention;

FIG. 2 is a sectional view of the lubricating pump mechanism taken alonglines 2-2 .of FIG. 1;

FIG. 3 is a side elevation of the pump mechanism shown in FIG. 2, partlyin section, taken along lines .3-3 of FIG. 2;

FIG. 4 is a diagrammatic sketch of the gearing of the pump mechanismshowing the planet gears in one position for reciprocation of the pumpplunger downwardly;

FIG. 5 is a diagrammatic sketch similar to FIG. .4 with the planet gearsin a second position for reciprocation of the pump plunger upwardly;

FIG. 6 shows diagrammatically the preferred planet gears for use in thepump construction of the invention;

FIG. 7 is a crosssection similar to that of FIG. 2 but omitting thegearing and pump drive shaft and showing the hand pump feature of theinvention; and

FIGS. 8 and 9 are diagrammatic sketches of the pump chamber, plunger andball check valves showing the plunger and valves in different operativepositions.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, andFIG. 1 in particular, there is shown a power-driven chain saw 10 havinga housing 12 which contains an electric motor (not shown) which isenergizable .by switch means (not shown) which maybe mounted in thehousing at a convenient locationconnectable to a source of electricityby electric conduit .13. The housing is givena tophandle I4andrearwardly extending handle 16 by means of which the chain sawcan beeasily heldand controlled during operation. The housingis provided witha.knob 18 which isintegral with a slidablehandpump 20 (see FIG. 7):tobedescribed in-detail.hereinafteLCap 2 2 is secured tothe housing inthe outlet of the lubricating oil reservoir. To add lubricating oil,itis merely necessary to-remove cap 22. Knobs '24 and Z26arerespectively the adjustment knob and cutter sharpening knob to beemployed for sharpening of the chain saw.

The front housing 28 of the saw chain encloses the sprocket end of thedrive shaft which carries the saw chain 32. One end of a guide bar 34 issuitably clamped within the housing 28. Guide bar 34 extends outwardlyof the housing and is provided with a slot or groove for receiving sawchain 32 thereon so that it can be guided along the periphery of theguide bar. A nose roller 35 is provided at the outer end of the guidebar to facilitate running and return of the saw chain. A lubricatingpump 36 supplies lubricating fluid such as a suitable oil to the grooveof the guide bar and/or the saw chain to permit smooth operation of thesaw chain. The construction of the lubricating pump will be hereinafterdescribed in detail.

As shown most clearly in FIGS. 2, 3 and 7 the lubricating pump 36 ismounted internally of the saw. The pump includes a plunger 38 which isslidably positioned within pump chamber 39 of a cylindrical bore 40formed in block 42. One or more pairs of rings 44 are positioned withincircumferential grooves of the plunger for sealing against the leakageof oil from the pump chamber past the plunger during the compressionstroke of the plunger.

Block 42 in the housing of the chain saw is provided with a pair ofpassageways 46, 48 which communicate respectively at one end via ballcheck valves 50, 52 with inlet and discharge conduits 54, 56 for thelubricating fluid. The other end of passageway 46 opens into the upperportion of cylinder 40. At such point the passageway is in communicationwith a duct which is formed in a sleeve member 58.

Sleeve 58 is mounted slidably in cylinder 40 and is urged normallytowards the upper extremity of its travel within the cylinder by spring60. Stop 62 is provided on the sleeve to limit the extent of its upwardand downward movement. The linear traverse of sleeve 58 is determined bythe depth of a transverse bore 64 formed in block 42 which actscooperably with stop 62. The sleeve is desirably provided with 0 rings61 in the same manner as plunger 38.

Sleeve 58 is given a central opening 66 by which lubricating fluid maypass from the reservoir (not shown) through inlet conduit 54, checkvalve 50, and passageway 46 into the pump chamber 39. A needle valve 68is seated in opening 66 and regulates the quantity of lubricant which iscaused to flow into the pump chamber. A slotted head 70 atop the needlevalve affords ready adjustment of the position of the needle valve withrespect to opening 66 to provide such regulation. Slotted head 70, asshown, is desirably nested within the confines of knob 18 which servesas the handle for a manual pump which will be described below.

Passageway 48, at its end remote from check valve 52, communicates withthe lower region of pump chamber 39 above the uppermost level to whichplunger 38 may be reciprocated. Thus, lubricating fluid within chamber39 and between the lower end face of sleeve 58 and the top surface ofplunger 38 may be pressured out of the chamber 39, through passageway48, check valve 52 and outlet conduit 56 to either the guide bar and/orsaw chain to supply lubricant thereto either by the upwardsreciprocation of the plunger during automatic operation of the pump orby the manual depression of knob or handle 18 which serves to lowersleeve 58 within cylinder 40.

From the foregoing it will be seen that knob or handle l8, sleeve 58 andpump chamber 39, in conjunction with the inlet and outlet passagewaysand conduits, provides a hand pump for the saw which is operableindependently of the automatic lubricating pump to be subsequentlydescribed.

Positioned within the housing for the saw, directly beneath block 42 andcradling the lower end thereof, is gear box 72. .lournaled rotatablywithin the gear box and supported by bearings 74 is drive shaft 76 whichmay conveniently be the shaft carrying the sprocket (not shown) for thesaw chain. Mounted on shaft 76 to rotate therewith is a sun element 78depicted in the form of a gear. Planetary members 80 and 82 arerotatably mounted within the gear box in driving engagement with and indiametrically opposed positions upon sun element 78. The planetarymembers 80, 82 are also shown in FIGS. 3 and 6 as being gears. However,it will be understood that the concept of the invention is equallyapplicable to the use of friction wheels or equivalent elements whichmay be drivingly engaged. Further, although two planetary members areshown it will be appreciated that by suitable design it is possible toemploy a single eccentrically shaped planetary member. A wobble ringshown in the form of an internal gear 84 with the teeth thereof inmeshed relationship with the planet gears surrounds same. Where theplanetary members employed take a form other than gears it will berecognized the gear ring 84 will take a complementary form. The internalgear, as shown in the presently preferred embodiment of the invention,is prevented from rotating by virtue of a keeper member 86 which iscarried fixedly by the portion of the gear box adjacent an appropriateregion of the internal gear. The internal gear at such region isprovided with a notch 88 therein within which the outer end of keepermember 86 is retained and which permits limited radial movement of gear84 relative to drive shaft 76 and gear box 72, principally along theline of motion of plunger 38; however, no rotation of the gear 84 ispermitted. It is to be understood, however, that the internal gear ring84 may be freely movable or rotatable. In such event, where gears areemployed, the specific gear ratios between the planet gears and theinternal gear are selected so as to effectuate the desired cyclical riseand fall of the ring gear through rotation of the planet gears withinthe internal gear ring at the desired rate relative to rotation of shaft76. By so designing the notch for the keeper member 86 the movement ofthe wobble ring can be so regulated that its motion is substantiallyalong the line of plunger reciprocation to thereby substantiallyeliminate any wiping action.

As shown in FIG. 3, the axes of the sun gear 78, planet gears 80 and 82and desirably also the internal gear 84 are aligned radially. It will beunderstood, however, that it is possible to achieve the desired resultswithout precise radial alignment. Preferably they are arranged along aline which is common to the reciprocal path of plunger 38 to minimizewiping of the plunger. However, it will be understood that precisealignment with the reciprocal path of the plunger is not essential tothe invention. The wobble ring 84 is provided with a collar 90 to whichis connected the lower end of plunger 38 to be reciprocated by thewobble ring in the manner to be described. In FIG. 2, the plunger isshown at its uppermost position ready to descend. As will be noted, bothof check valves 50, 52 are closed by the seating of the balls in bothvalves by their respective associated springs. The hand pump 20 is shownin its normally inoperative state.

The diametral pitch of the sun gear, planet gears and internal gear isdesirably the same to insure smoothness of action between such gears.The planet gears 80, 82 should be provided with a dissimilar number ofteeth. According to the presently preferred embodiment planet gear 80 isprovided with one tooth more than planet gear 82. Where all of theaforementioned gears have a diametral pitch of 32 the number of teeth ongears 80 and 82 should thus be 20 and 19 respectively.

Due to the difference in the number of teeth pro vided on the planetgears, and the provision of either a nonrotatable internal gear or asuitable selection of gear ratios between the planet gears and internalgear it will be appreciatedthat the planet gears, upon rotation of driveshaft 76 and its associated sun gear 78, will walk around the internalgear. When planet gear 80 reaches the zenith of its path within theinternal gear, as depicted in FIG. 5, planet gear 82 will be located atits lowermost point. In this rotative position the wobble ring will becaused to rise a distance which is determined by the difference in thenumber of teeth carried by the planet gears and the diametral pitch ofsuch gears. Where, as aforesaid, planet gear 80 is provided with 20teeth and planet gear 82 is provided with 19 teeth and the diametralpitch for the gears is 32, the wobble ring (internal gear 84) will rise1/32 inch. This in turn, willeffect an upward movement of plunger 38 bythe same amount. In FIG; 4, the planet gears have walked to apositionreverse from thatshown in FIG. 5 to thereby effectuate a drop of1/32 by the wobble ring and plunger.

It will be further appreciated that by selective design of the gearingone can provide for the desired stroke of the plunger and therebydeliver any designed quantity of lubricant to the saw chain and/or guidebarper unit time. The present specification has not been encumbered witha disclosure of the conduits needed to convey lubricant from dischargeconduit 56 to the exact point of distribution or to supply lubricantfrom the reservoir to inlet conduit 54 since various arrangements may beemployed and it is well within the knowledge of persons skilled in thisart to provide such conduitry.

FIG. 6 illustrates diagrammatically the relative sizes of planet gears80, 82 having the same diametral pitch but a different number of teeth.The difference in diameter d will be a function of the difference in thenumber of teeth and the diametral pitch. As stated above, where theteeth on planet gears 80 and 82 are 20 and 19 respectively, and thediametral pitch is 32, d will be l/32 inch.

FIG. 7 depicts the hand pump 20 in its actuated state. Knob or handle 18has been depressed, thereby forcing sleeve 58 downwardly into pumpchamber 39. Such movement of the sleeve induces a flow of lubricant frominlet conduit 54, through the check valve 50 (thereby urging the ball 94against the force of spring 96 to open the valve), through passageway46, into the passage through sleeve 58 and into pump chamber 39. Furtherdownward movement of the sleeve 58results in the flow of lubricant intopassageway 48 and against the spring-biased ball 100 of check valve 52.Thelubri- 6 cant is thus forced into discharge conduit 56 and'out to thepoint or points of distribution. It will thus be seen that hand pump 20is actuable independently of the automatic lubricating pump 36 whichutilizes plunger 38, the gearing of gear box 72, etc.

FIGS. 8 and 9 show the path of lubricant through the check valves 50, 52by the arrows indicated therein. It will be seen that lubricant is drawninto pump chamber 39 through check valve 50 upon downward movement ofplunger 38. During such descent of the plunger the pressure of lubricantupstream of the ball 94 causes a compression of spring 96, opening thevalve and permitting a flow of lubricant into the pump chamber 39. Sincethe volume of chamber 39 above the plunger 38 is increasing, there isinsufficient build-up of pressure to unseat ball 100. However, as shownby the diagrammatic sketch of FIG. 9, as the plunger rises withincylinder 40the actual pumping chamber 39 diminished in volume with aresultant increase in pressure on the lubricant contained therein. Theend result is thatonce the pressure increases sufficiently it causes theunseating of ball and the flow of lubricant through the check valve 52to discharge conduit 56 and to distribution. During the ascent of theplunger the elevated pressure within chamber 39 serves to insure seatingof ball 94 on its seat to retain check valve 50 in its closed condition.The operation of ball check valves is not novel per se; however, whencombined with the unique handand automatic lubricating pump constructionhereinbefore described the use and positioning of check valves 50, 52 isparticularly effective.

Numerous alterations of the structure herein disclosedwillsuggestthemselves to those skilled in the art. However, it is to be understoodthatthe present disclosure relates to a preferred embodimentoftheinvention which is for purposes ofillustration only and not to beconstrued as a limitation of the invention. All such modifications whichdo not depart from the spirit of the invention are intended to beincluded within the scope of the appended claims.

Having thus set forth the nature of the invention, what is claimedherein is:

1. In a power-driven chain saw having a saw chain and a saw thereon, asprocket shaft rotatably supporting said chain, a guide bar for guidingsaid saw chain along a predetermined path, and :a lubricating pump whichincludes a reciprocable plunger for supplyinglu bricant for said sawchain, the improvement which comprises:

a. a wobble ring mounted so as to cyclically reciprocate said plunger ina predetermined time-phase relationship with the rotation of said sawchain;

b. a sun element mounted within said wobble ring operably connected tothe driving means for said chain saw; and

c. at least one planetary member interposed between said sun element andsaid wobble ring, the relation ship between said planetary member andsaid wobble ringbeing such that said planetary member rotates withinsaid wobble ringto periodically reach positions therewithin whereby saidwobble ring is caused to rise and fall and thus cause reciprocation ofsaid plunger.

2. A power-driven chain saw according to claim 1,

5 wherein said wobble ring comprises an internal gear ring, said sunelement comprises a sun gear, and said planetary member comprises a pairof planetary gears.

3. A power-driven chain saw according to claim 2, wherein the first ofsaid planetary gears has a greater number of teeth than the other ofsaid planetary gears.

4. A power-driven chain saw according to claim 3, wherein said internalgear ring is mounted so as to be non-rotatable but movable along a linewhich is substantially common to the reciprocal path of said plunger.

5. A power-driven chain saw according to claim 1, wherein a housing isprovided for said pump which comprises a block having a cylindrical boretherein, said plunger being slidably positioned within said cylindricalbore and defining the lower wall of a pump chamber therein, inlet andoutlet passages being provided in said block communicating with saidpump chamber for the admission thereto and the withdrawal therefrom oflubricating fluid.

6. A power-driven chain saw according to claim 2, wherein said first andsecond planet gears have their axes of rotation located along a linepassing radially through the axis of rotation of said sun gear; saidline substantially defining the principal line of motion of saidplunger.

7. A power-driven chain saw according to claim 6, wherein the diametralpitch of said ring gear, sun gear and said first and second planet gearsis the same.

8. A power-drive chain saw according to claim 6, wherein said sun gearis mounted by the sprocket drive shaft.

9. A power-driven chain saw according to claim 8, wherein the housingfor said pump is associated with the transmission housing for the chainsaw.

10. A power-driven chain saw according to claim 4, wherein a notch isprovided in said ring gear and a keeper member is carried fixedly by thehousing which surrounds at least the portion of said ring gear gavingsaid notch therein, said keeper member extending into said notch toprevent rotation of said ring gear and permitting limited radialmovement thereof principally along the line of motion of said plunger.

11. A power-driven chain saw according to claim 5, wherein a combinationhand pump and needle valve is slidably mounted within the cylindricalbore of said pump housing, said needle valve being in communication withsaid lubricating fluid inlet and with the upper portion of said pumpchamber whereby the amount of lubricating fluid which is drawn into saidchamber may be regulated.

12. A power-driven chain saw according to claim 11, wherein saidcombination hand pump and needle valve comprises a sleeve positionedwithin the upper region of said cylindrical bore having its lower endface in spaced relation to said plunger, said needle valve being carriedwithin said sleeve and movable axially thereof so as to regulate theamount of lubricant flowable through said sleeve into said pump chamber.

13. A power-driven chain saw according to claim 11, wherein spring meansis mounted within said cylindrical bore to bias said hand pump into anormally inoperative position.

14. A power-driven chain saw according to claim 5, wherein saidlubricating fluid inlet and outlet passages are provided withspring-loaded ball check valves to prevent back flow of lubricatingfluid.

1. In a power-driven chain saw having a saw chain and a saw thereon, asprocket shaft rotatably supporting said chain, a guide bar for guidingsaid saw chain along a predetermined path, and a lubricating pump whichincludes a reciprocable plunger for supplying lubricant for said sawchain, the improvement which comprises: a. a wobble ring mounted so asto cyclically reciprocate said plunger in a predetermined time-phaserelationship with the rotation of said saw chain; b. a sun elementmounted within said wobble ring operably connected to the driving meansfor said chain saw; and c. at least one planetary member interposedbetween said sun element and said wobble ring, the relationship betweensaid planetary member and said wobble ring being such that saidplanetary member rotates within said wobble ring to periodically reachpositions therewithin whereby said wobble ring is caused to rise andfall and thus cause reciprocation of said plunger.
 2. A power-drivenchain saw according to claim 1, wherein said wobble ring comprises aninternal gear ring, said sun element comprises a sun gear, and saidplanetary member comprises a pair of planetary gears.
 3. A power-drivenchain saw according to claim 2, wherein the first of said planetarygears has a greater number of teeth than the other of said planetarygears.
 4. A power-driven chain saw according to claim 3, wherein saidinternal gear ring is mounted so as to be non-rotatable but movablealong a line which is substantially common to the reciprocal path ofsaid plunger.
 5. A power-driven chain saw according to claim 1, whereina housing is provided for said pump which comprises a block having acylindrical bore therein, said plunger being slidably positioned withinsaid cylindrical bore and defining the lower wall of a pump chambertherein, inlet and outlet passages being provided in said blockcommunicating with said pump chamber for the admission thereto and thewithdrawal therefrom of lubricating fluid.
 6. A power-driven chain sawaccording to claim 2, wherein said first and second planet gears havetheir axes of rotation located along a line passing radially through theaxis of rotation of said sun gear; said line substantially defining theprincipal line of motion of said plunger.
 7. A power-driven chain sawaccording to claim 6, wherein the diametral pitch of said ring gear, sungear and said first and second planet gears is the same.
 8. Apower-drive chain saw according to claim 6, wherein said sun gear ismounted by the sprocket drive shaft.
 9. A power-driven chain sawaccording to claim 8, wherein the housing for said pump is associatedwith the transmission housing for the chain saw.
 10. A power-drivenchain saw according to claim 4, wherein a notch is provided in said ringgear and a keeper member is carried fixedly by the housing whichsurrounds at least the portion of said ring gear gaving said notchtherein, said keeper member extending into said notch to preventrotation of said ring gear and permitting limited radial movementthereof principally along the line of motion of said plunger.
 11. Apower-driven chain saw according to claim 5, wherein a combination handpump and needle valve is slidably mounted within the cylindrical bore ofsaid pump housing, said needle valve being in communication with saidlubricating fluid inlet and with the upper portion of said pump chamberwhereby the amount of lubricating fluid which is drawn into said chambermay be regulated.
 12. A power-driven chain saw according to claim 11,wherein said combination hand pump and needle valve comprises a sleevepositioned within the upper region of said cylindrical bore having itslower end face in spaced relation to said plunger, said needle valvebeing carried within said sleeve and movable axially thereof so as toregulate the amount of lubricant flowable through said sleeve into saidpump chamber.
 13. A power-driven chain saw according to claim 11,wherein spring means is mounted within said cylindrical bore to biassaid hand pump inTo a normally inoperative position.
 14. A power-drivenchain saw according to claim 5, wherein said lubricating fluid inlet andoutlet passages are provided with spring-loaded ball check valves toprevent back flow of lubricating fluid.